Preheat oven to 325 degrees (F). Line a baking sheet with parchment paper or a silicone baking mat. Set aside.
In a medium bowl combine the coconut flakes, sweetened condensed milk, and vanilla. Mix fully and set aside.
Using a hand mixer or a stand mixer beat the egg whites until stiff peaks form. Gently fold the egg whites in the coconut mixer until fully combined.
Scoop about 1 tablespoonful of the mixture onto the prepared baking dish. Leaving about an inch between each cookie. Flatten the cookies so they are about 1/2 inch thick.
Bake the cookies for 20-25 minutes, rotating the pan often until the edges of the cookies are browned.
Allow the cookies to cool for a couple of minutes and then use your thumb or the back of a spoon to make a small indention in the center of each cookie.